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No. 43,819.- PATENTED AUG. 9, 1864.

0. H. WILLOOX. SEWING MACHINE.

2 SHEETS-SHEET 1.

fi MA Wz'm 6.5.565

No. 48,819. PATENTED AUG. 9, 1864.-

G. H. WILLOOX.

SEWING MACHINE.

2 SHEETS-SHEET 2.

fnvenior WZ'ZZLGSSG; I /l. X KM NITED STATES- PATENT OFFICE.

CHARLES H. \VJLLOOX, OF NEW YORK, N. Y., ASSIGNOR "[0 JAMES \VILLCOX, I

or sA'Mn PLACE.

IMIPROVEMENTIN SEWING-MACHINES.

Specification forming part of- Letters Patent No. 43,819, dated August 9, 186 1.

To all whom it may concern.-

Be it known thatv I, CHARLES H. \VILLGOX,

of New York, in the county and State'of New' York, have invented certain new and useful lmprtwements in Sewing-Machines; and I do hereby declare that the following is a full, clear, and exact description of the same, reference being bad to the accompanying drawings, in which- Figure 1 represents a front and Fig. 2 a side view of part of a sewing-machine to which my improvement is applied. v In all sewing-machines the tension holds its place as one of the most important of the devices constituting the machine, as upon it depends the proper tightness of the thread to produce perfect sewing. It is also the most diffieult to regulate or adjust, as it has to be varied to suitthe ever-varyingsize ofthe thread, length otstitch, and thickness or nature of material being sewed. It will readily be seen what a constant soureeof trouble it is to the opera-. I tor, since at each change of thread, stitch, or

material the tension must be regulated accordingly before proceeding to sew.

To niake a tension which would beautomatic in its operation, and such as will require no change or alteration by the operator for every required variety of work, although yery desirable,would seem to be almost impossible. This result, however, is accomplished bythe simple device I am about to describe. 0f its usefulness there can be no question, as by making the tension automatic the one constant'so'uree of trouble and anxiety to the operator on a sew: lug-machine is removed; at the same time perfeet work, as far as the tension is concerned, is

secured, fonby this device, the thread is always drawn up to the proper tightness, whatever may be the material and thread used.

My improvement therefore relates to a tension device to be used in connection with any sewing-machine, whether the same be operatiu g with a single or double thread, in which the thread or one of the threads is supplied to an eye-pointed needle from a spool orbobbin; and my invention consists in the employment of a suitable apparatus for holding, the thread firmly in a sewing-machine untilvthe loop or stitch at which point it is suddenly -released, little or no tension being applied to the thread. By the use of this'apparatu's no adjustment of the tension will ever be required by the operator. This apparatus may be'applied to all'sewingmach'ines,suitable minor modifications being requisite for each class of machine; but as applied to the machine known as Willcox 8a Gibbs it will consist of two glass or metal disks moving freely upon a headed spindle'screwed in't-o the'frame of the machine, one of the disks being made to approach toward the otherby means otka lever worked by-a suitable camor eecentrio, which is so shaped as to hold .the disks together and nip the thread between them dur ing a certain portion ofits revolution and then to release them. The thread should be allowed to unwind freely from the spool,- passiug thence direct between the nipping-disks, whence ti.

periphery of which cam, from qto p, is concentrio with the center of the shaft. Atp the pe-- riphery suddenly approaches the center, after which it gradually recedes, and by an easy curve regains the full diameter at q.

To the front end, N, of the spool-stand O is hinged, by means of the fulcrum-pin K, the leverD, the lower endof which bears againstandf is caused to follow the motionof the cam G, by mean'sof the spring H acting upon the-op- 'posite side of the said cam. The stud-screw I F, on, which are loosely fitted the two disks or washers E,the washer L, and the spiral spring M, (shownby dotted lines in Fig. 2,) is passed through a hole in the lever D oflsutficient diameter to permit of the free movement of the spiral spring M, and is screwed firmly into the spool-stand O.

P represents a spool, on which is wound the thread i".

The operation is substantially as follows: The thread 1' from the spool P passes through the thread-guide J, and thence between the. two washers E, partly round the stud F, and

is nearly or wholly drawn up to the material, 1 out from between the washers at rightangles,

to be acted upon by the needle and looper or thread 1', firmly between the washers L and the head of the stud F, in which position they are held by that portion of the cam between q and puntil by the operation of the looping or other devices the'loop or stitch is drawn up nearly or quite to the surface of the cloth. When atp the lever is suddenly released and allowed to approach the center of the shaft, and thereby relieves the washers E of all the pressure, except the slight pressure exerted by the spiral spring M, which causes sufiicient friction .to prevent too much thread being jerked through between the washers upontheir sudden release'by the lever 1). The, continued revolution ofthe cam would observe that I lay no claim to the clampiug or nipping of the needle-thread, nor to the special devices herein shown for efiecting'that; but

1 claim The combination of devices fo'r producing in sewing-machines a self-acting intermittent tension of the needle-thread. by holding such thread'rigidlybetween suitable nipping-surfaces until the stitch or loop is nearly or quite drawn upto the surface of the material being s'cwed,aud then releasing the thread suddenly,

' so as to allow sufficient thread to be drawn through the apparatus with little or no tension or friction for the forming of the next stitch, 4 

